Many types of power turf mowing equipment are known. Such equipment can generally be classified as those mowers which include a rotary cutting unit(s) or those which include a reel cutting unit(s). A rotary cutting unit usually includes one or more rigid, generally straight, steel blades rotated within a housing about a vertical axis to sever grass or other vegetation at a predetermined height above the ground. A reel cutting unit, on the other hand, typically includes a frame within which is horizontally rotatably mounted a reel possessing a plurality of arcuate blades. The rotating reel blades pass in close proximity to a bedknife which spans the cutting unit frame parallel to the horizontal reel axis. Grass blades are sheared at the reel blade/bedknife interface.
While rotary cutting units are suitable for many purposes, it is generally perceived that reel units provide a higher quality cut. The present invention relates to reel-type turf mowers, and the remainder of this discussion will focus on same. As is well known, another reel-like unit is used to produce a "verticut," and this type of cutting unit is also contemplated.
Power turf mowing equipment can also be categorized based on the method of propelling the cutting units. Generally, there are walk-behind, riding, and towed turf mowers. The present invention relates primarily though not exclusively to riding turf mowers, and for the sake of brevity the invention will hereafter be discussed in terms of commercial riding mowers having one or more reel cutting units.
Riding reel-type turf mowers typically include a traction vehicle supported by a plurality of wheels, including one or more traction wheels; a prime mover supported by the vehicle frame and connected through a transmission to the traction wheel(s); one or more reel-type cutting units, powered by the prime mover through belts or hydraulic motors, for example; and a cutting unit suspension system interposed between the cutting unit(s) and the vehicle. Some reel-type turf mowers, e.g., those intended for use on golf greens, also include grass collection systems to collect the clippings rather than allowing them to fall to the turf.
The present invention relates most directly to riding mowers of the type used in golf greens. In this type of mower, the cutting unit suspension system often includes two rather distinct subsystems, namely a lift system (often including a so-called lift arm) and a cutting unit propulsion system (often including a so-called carrier frame). The lift arm in such mowers lifts the cutting unit from its lowered, operating position but is not involved in propelling the cutting unit across the turf. Likewise, the carrier frame propels the cutting unit but is not involved in lifting the cutting unit from its operating position to its transport position. One historical problem with such mowers is that the carrier frame is usually supported at its front and by a roller that engages the turf just prior to the cutting unit, and the roller tends to compress or mat the turf thus interfering to some degree with the cutting operation.
Over the years, much effort has been directed to improving the quality of cut afforded by reel-type mowers. These efforts have been concentrated primarily in two areas, namely the cutting units themselves and the cutting unit suspension systems. The present invention relates to an improved cutting unit and grass collection system; and to a unique cutting unit suspension technique, which can collectively address any of a wide variety of long-standing problems associated with such mowers, including but not limited to "floating" the cutting unit; reducing turf matting and compaction by the carrier frame roller; and providing a good "seal" between a "floating" cutting unit and a traction vehicle supported grass catcher. Each of these particular examples of problems which can be addressed by the reel mower of the present invention is discussed below.